Specifications

Reference Guide
7-39
WAN Card WAN Card User Screens and Settings
The choice of
c-fdl
disables telco-side capability to access performance-monitoring
information. The
c-fdl
option sends and receives network management information over the
facility data link. The
c-b7r
option sends and receives the same information over time slot 24
on the T1 WAN link highlighted. The
e-fdl
option sends and receives T1 ESF-encapsulated
network management information over the FDL.
EER THRHD
The Excessive Error Rate Threshold selects the error rate, which an alarm is declared. This
setting interacts with the EER setting in the Alarm Filters of the system. The options are
10e-4
through
10e-9
, or
none
.
RDNT RULES
The selection of Redundancy Rules will define the method of determining what event will
trigger a WAN port to switch to its redundant mate. The options are
none
,
OOS,
and
CGA
.
GROUP
The Group setting identifies a method of link-fail alarm propagation from upstream trunks to
downstream tributaries when the system is configured for alarm transcoding.
The selection of a group is a two-step process. After identifying the group number (
1
to
4
),
select the secondary group (
A
[child group],
B
[child group] or
C
[parent group]).
Figure 7-26 shows two system units with "parent-child" groupings. The child groups are
designated as "A" and "B." The parent groups are designated "C”. Using WAN Groups
The WAN links between the Device and the System Unit (A, B, A1, and B1) are called
tributaries
. The WAN link between the two SYS Units (C and C1) is referred to as a
trunk
.
In the normal condition (no WAN groups selected), a failure on any of the tributaries supplying
Device 1 would be reported at SYS 1 and Device 1 only. A failure of the trunk from C to C1
would be reported at SYS 1 and 2 only.
When Groups are created at both system units, a trunk failure (C to C1) will inform all of the
associated tributaries (A and B, A1 and B1) of that condition.
When groups are used in conjunction with the Network Management option (mentioned
earlier) and the AIS/ALM is set to
tcodr
, a failure of any of the tributaries will propagate the
failure through the trunk to the associated tributary at the other end (A to A1 or B to B1).